Work towards a fully operational, dual planar imaging system continued during this period on both the electronic and mechanical elements of the system. The mechanical design of the imaging bed/support arms for the camera was finalized and during a period of several months, fabricated,in final form. This unit is now in the Department of Nuclear Medicine and is available for use. Work on the electronic components of the system was accelerated. Installation and software of two data acquisition boards was completed permitting image data to be acquired with the MAC II microcomputer. Several iterations of hardware and software were undertaken resulting in a system capable of acquiring all forms of nuclear image data. Performance of the two (positron-sensitive photomultiplier tube based) scintillation cameras was intensively investigated and a body of performance data now exists that characterizes most of the essential properties of these tubes/cameras, eg. spatial resolution, spatial linearity, etc., as well as indicating important limitations, eg. spatial dependent tube gain. Correction circuits for improving spatial linearity and gain uniformity have been designed and are now being fabricated for testing.